JEE MAIN - Physics (2005 - No. 26)
In the circuit, the galvanometer $$G$$ shows zero deflection. If the batteries $$A$$ and $$B$$ have negligible internal resistance, the value of the resistor $$R$$ will be -
$$100\Omega $$
$$200\Omega $$
$$1000\Omega $$
$$500\Omega $$
Explication
$$iR = 2 = 12 - 500i$$
$$\therefore$$ $$i = {1 \over {50}}$$
$$\therefore$$ $${1 \over {50}} \times R = 2$$
$$R = 100\Omega $$